============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- ksoftirqd/0/16 is trying to acquire lock: ffff888076daf218 (&qs->lock){-.-.}-{2:2}, at: __queue_map_get+0x11c/0x4b0 kernel/bpf/queue_stack_maps.c:105 but task is already holding lock: ffff88802795aa18 (&qs->lock){-.-.}-{2:2}, at: queue_stack_map_push_elem+0x171/0x5f0 kernel/bpf/queue_stack_maps.c:210 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&qs->lock); lock(&qs->lock); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by ksoftirqd/0/16: #0: ffffffff8cd2ff40 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ff40 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2188 [inline] #0: ffffffff8cd2ff40 (rcu_callback){....}-{0:0}, at: rcu_core+0xc51/0x1720 kernel/rcu/tree.c:2467 #1: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #1: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #1: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline] #1: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0xf4/0x400 kernel/trace/bpf_trace.c:2362 #2: ffff88802795aa18 (&qs->lock){-.-.}-{2:2}, at: queue_stack_map_push_elem+0x171/0x5f0 kernel/bpf/queue_stack_maps.c:210 #3: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #3: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #3: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline] #3: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xde/0x3c0 kernel/trace/bpf_trace.c:2361 stack backtrace: CPU: 0 PID: 16 Comm: ksoftirqd/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain kernel/locking/lockdep.c:3856 [inline] __lock_acquire+0x5d40/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162 __queue_map_get+0x11c/0x4b0 kernel/bpf/queue_stack_maps.c:105 bpf_prog_00798911c748094f+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1223 [inline] __bpf_prog_run include/linux/filter.h:612 [inline] bpf_prog_run include/linux/filter.h:619 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline] bpf_trace_run2+0x1d1/0x3c0 kernel/trace/bpf_trace.c:2361 __bpf_trace_contention_end+0xdd/0x130 include/trace/events/lock.h:122 trace_contention_end+0xe6/0x110 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x7ec/0x9d0 kernel/locking/qspinlock.c:560 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x24e/0x2c0 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xb4/0xf0 kernel/locking/spinlock.c:162 queue_stack_map_push_elem+0x171/0x5f0 kernel/bpf/queue_stack_maps.c:210 bpf_prog_216c997a1f42e404+0x3f/0x43 bpf_dispatcher_nop_func include/linux/bpf.h:1223 [inline] __bpf_prog_run include/linux/filter.h:612 [inline] bpf_prog_run include/linux/filter.h:619 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline] bpf_trace_run3+0x1e7/0x400 kernel/trace/bpf_trace.c:2362 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] kmem_cache_free+0x1e0/0x280 mm/slub.c:3851 vma_lock_free kernel/fork.c:472 [inline] __vm_area_free+0xe4/0x110 kernel/fork.c:528 rcu_do_batch kernel/rcu/tree.c:2194 [inline] rcu_core+0xcc4/0x1720 kernel/rcu/tree.c:2467 handle_softirqs+0x280/0x820 kernel/softirq.c:578 run_ksoftirqd+0x9c/0xf0 kernel/softirq.c:950 smpboot_thread_fn+0x635/0xa00 kernel/smpboot.c:164 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293